@P.Knowsley: Kundal is something G. is definitely going to speak about, still, unless i make them both appear at the same time in the city, Grigori should appear the next time they get back to town....or is making them appear togheter exactly what you suggested..?
Or at least, at the same time.
I presented both to my players as ongoing events that had started happening
whilst they were out of town. They were in fact completely unrelated in my
story, but there's no reason why they couldn't be related in yours...
e.g. K is brought along by G & released in order to cause trouble which he can
then stir along with his particular talent set...
(It took my PCs a little bit to figure out that they were unrelated...)
As for the last one with Malgorzata - just because of the way things ran in my
game - that got introduced at the very end of the 2nd book, & it was something
that came up at a council meeting (Because I was out of options.)
Up to you - but feel free to play around with how things are introduced...